jmicky41,
Obviously HLLE is a complicated topic, but there is tons of misinformation out there. What I was trying to say is that most cases of completely resolved HLLE included moving the fish to a new (better) tank at some point. Straight diet changes with everything else remaining unchanged does not work in the vast majority of cases, and in the cases where diet change alone has purported to cure the fish, there was very often another change that went unidentified (these run the gamut of installing a skimmer, changing brands of carbon, changing the substrate, cleaning out the sump, etc.).
I've determined to my own satisfaction that carbon fines (dust) from certain brands of carbon initiates HLLE. This is "proven" as far as I'm concerned. I strongly suspect that we will ultimately find that all cses of acute HLLE and some chronic cases of HLLE are caused by particulate matter in aquariums causing damage to the fish's lateral line pores.
Jay
p.s. - just for my own curiosity - how large is that fish and is it skinny like the others saw?